November 2017 - Msepostdoc-list

Seminar Notice for Jorge A. Ramirez's Preliminary Exam on Dec. 1, at 8:00 a.m., in IMI 127; Exam at 10:00 a.m., in IMI 127 "Voids and Continuous Fibers in Extrusion Deposition Additive Manufacturing of composite Materials"
by Son, Rosemary E 27 Nov '17

27 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Voids and Continuous Fibers in Extrusion Deposition Additive Manufacturing of Composite Materials" By Jorge A. Ramirez Purdue MSE Ph.D. Preliminary Exam Advisor: Professor R. Byron Pipes ABSTRACT Extrusion Deposition Additive Manufacturing (EDAM) is a layer-by-layer three-dimensional manufacturing process. This process consists of the liquefaction and pressurization of pelletized material inside an extruder, the material melt is then deposited onto a build platform to create a physical object. The incorporation of an extruder allows EDAM to process a wide range of materials. The Composites Manufacturing and Simulation Center (CMSC) at Purdue has explored the use of this technology with highly filled polyphenylene sulfide (PPS) with carbon fibers (50 wt%) for composites tooling applications. Advantages of EDAM in tooling manufacturing include reductions in lead time and cost. In addition, EDAM allows for a high degree of customization and optimization. Properties of EDAM parts are directly dependent on their final microstructure. In this work, I discuss two key microstructural features, voids and fiber orientation state, and how they are dictated by different processing parameters. Lastly, I discuss the implementation of reinforcing continuous fibers with EDAM for rapid fabrication of structural components. Date: Friday, December 1, 2017 Time: 8:00 A.M. Place: IMI 127 School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2200 West Lafayette, IN 47907 765-494-4105

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Reminder for Seminar for Juan Alfonso Campos's Prelim Exam, Tuesday, Nov. 28, at 1:30 p.m., in ARMS 1109. Professors note that Exam will be Nov. 30, at 1:30 p.m., in ARMS 2119
by Son, Rosemary E 27 Nov '17

27 Nov '17

Committee Members (Professors) note that the exam will be Nov. 30 at 1:30 p.m., in ARMS 2119. Seminar is Nov. 28, at 1:30 p.m., in ARMS 1109 Please consider attending the following: MATERIALS ENGINEERING SEMINAR “Microstructural Models for Porous Rechargeable Lithium-Ion Batteries” By Juan Alfonso Campos Purdue MSE Ph.D. Preliminary Exam Advisor: Professor R. Edwin García ABSTRACT A porous electrode was regarded as a solution to the rampant requirements of energy and power densities coming from the high technology electronic devices. However, the underlying composite character made it a complicated system to model. In nature, it is an electrochemical system of known reactions, but requires to be modeled as a multiphase, multicomponent system, where kinetic reactions take place between atomic and microscopic length scales; although, the design parameters and desired eﬀects are macroscopic. A review of pros, cons, limitations and scope of the state of the art models was provided. Volume averaging models revealed an existent successful implementation of phase transitions, a methodology to determine 1-D model validity, and eﬀects of tortuosity estimation in model ﬁdelity. Microstructurally resolved models, shown the consequences of particle to particle interactions, particle morphology eﬀects, and the computational burden diﬀerence in favor of averaging models for pragmatic design. Consequently, it was proposed a rigorously homogenized macroscale model enhanced with microstructural eﬀects, and based on preliminary results, a non-heuristic method to decide applicability of existing models when electrode microstructure is known. Date: Tuesday, November 28, 2017 Time: 1:30 P.M. Place: ARMS 1109

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Fwd: Seminar Thursday December 7 at 1:30 pm in ME 2054 Dr. Yonggang Huang
by Donna Bystrom 21 Nov '17

21 Nov '17

Dear All, Please mark your calendars for the upcoming seminar with Dr. Yonggang Huang Thursday December 7, 1:30 to 2:30 in ME 2054. Please see attachment

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Seminar Notice for Diana Heflin's Preliminary Exam, Thursday, Nov. 30, at 12:30 p.m., in IMI 127. "Mechanisms for Combining Polyamide and Epoxy and Their Effects on Mechanical Performance"
by Son, Rosemary E 20 Nov '17

20 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Mechanisms for Combining Polyamide and Epoxy and Their Effects on Mechanical Performance" By Diana G. Heflin Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Jan-Anders Mansson ABSTRACT This work provides an in-depth study in the various methods for toughening epoxy resin with polyamide across a range of length scales-from the atomic to the macroscopic. This allows for a fundamental understanding of the epoxy-polyamide system, as many of the atomic interactions and their kinetics inform the macroscopic mechanical properties. The kinetics of the epoxy-polyamide reaction prove that covalent bonding is energetically favorable, enabling chemical crosslinking between epoxy and polyamide. The two polymers can then mechanically interlock under a number of different processing conditions, including forming a homogeneous mixture of the two, incorporating the polyamide into the epoxy in the form of fine particles, or adding the polyamide to an epoxy-fiber composite. Though each of these methods allows for the tailoring of processing conditions and final structures to an individual use, the literature shows that the underlying physical and chemical interactions can be applied to all epoxy-polyamide systems. Thus, lessons learned through the study of one epoxy-polyamide structure can be valuable in predicting the behavior of other epoxy-polyamide mixtures. Further, many findings presented in this work can be extended to other combinations of dissimilar polymers. Date: Thursday, November 30, 2017 Time: 12:30 P.M. Place: IMI 127

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Seminar Notice for Juan Alfonso Campos's Prelim Exam, Tuesday, Nov. 28, at 1:30 p.m., in ARMS 1109. "Microstructural Models for Porous Rechargeable Lithium-Ion Batteries"
by Son, Rosemary E 20 Nov '17

20 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR “Microstructural Models for Porous Rechargeable Lithium-Ion Batteries” By Juan Alfonso Campos Purdue MSE Ph.D. Preliminary Exam Advisor: Professor R. Edwin García ABSTRACT A porous electrode was regarded as a solution to the rampant requirements of energy and power densities coming from the high technology electronic devices. However, the underlying composite character made it a complicated system to model. In nature, it is an electrochemical system of known reactions, but requires to be modeled as a multiphase, multicomponent system, where kinetic reactions take place between atomic and microscopic length scales; although, the design parameters and desired eﬀects are macroscopic. A review of pros, cons, limitations and scope of the state of the art models was provided. Volume averaging models revealed an existent successful implementation of phase transitions, a methodology to determine 1-D model validity, and eﬀects of tortuosity estimation in model ﬁdelity. Microstructurally resolved models, shown the consequences of particle to particle interactions, particle morphology eﬀects, and the computational burden diﬀerence in favor of averaging models for pragmatic design. Consequently, it was proposed a rigorously homogenized macroscale model enhanced with microstructural eﬀects, and based on preliminary results, a non-heuristic method to decide applicability of existing models when electrode microstructure is known. Date: Tuesday, November 28, 2017 Time: 1:30 P.M. Place: ARMS 1109

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Reminder: Seminar for Tae Hoo Chang's Preliminary Exam, Tuesday, Nov. 21, 8:30 a.m., in ARMS 1021. " Fabrication of Aptamer Sensors Using by Plasmonically Engineered Nanoprobes"
by Son, Rosemary E 20 Nov '17

20 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Fabrication of Aptamer Sensors Using by Plasmonically Engineered Nanoprobes" By Tae Hoo Chang Purdue MSE Ph.D. Preliminary Exam Advisors: Professors Alexander Wei and Lia A. Stanciu ABSTRACT As society is getting complicated and developed, people are easily stressed out. Cortisol is a well-known stress indicator hormone. Balancing this hormone in daily life is very important because it affects all our body such as metabolism, blood pressure, and physiological processes. Abnormal elevation of this hormone can be a cause of Cushing's syndrome and kidney disease. Hence, the detection of cortisol level in the body can be a key way to prevent related diseases. To detect cortisol level, we need to take cortisol from different sources. The best source for collecting cortisol is urine or saliva because of the requirement of 24 hour sample collection and non-invasive methods. However, these sources have limited amount of cortisol concentration. Therefore, a new highly sensitive nanosensor with low detection limits is needed. In this work, I will review the trends of cortisol sensors at first. Then, I will suggest a noble sensor platform called "Nano-brightener" sensor. This sensor platform has many benefits such as low cost, easy to sensing and non-invasive detection in urine. Moreover, the strongest point is that this sensor is suitable for the point-of-care monitoring systems because this sensor will be compatible with smart phone camera at the end of this project. This cortisol sensor composes four components: silver nanoparticle (AgNP), DNA aptamers, transducer core, and fluorescent dye. By using plasmon resonant AgNPs, the fluorescent dye can turn on/off due to the metal-enhanced fluorescence (MEF) effect. We will discuss not only the submerged fundamental principles of this aptamer sensor but also the roll of each component and how to fabricate it. At the end of presentation, preliminary results and future plans will be introduced. Date: Tuesday, November 21, 2017 Time: 8:30 A.M. Place: ARMS 1021

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Reminder: Seminar for Christopher McCleary's MS Final Exam, Tuesday, Nov. 21, at 1:00 p.m., in HAMP 2107, "Mechanical Testing of Semi-Solid AL-MG Binary and 7050 Aluminum Alloys Using the Reheating Cooling Method"
by Son, Rosemary E 20 Nov '17

20 Nov '17

MATERIALS ENGINEERING SEMINAR "Mechanical Testing of Semi-Solid AL-MG Binary and 7050 Aluminum Alloys Using the Reheating Cooling Method" By Christopher J. McCleary Purdue MSE MS Final Advisors: Professor David R. Johnson and Matthew J. M. Krane ABSTRACT Elevated temperature tensile testing beyond the non-equilibrium solidus demonstrates the advantage of a new method called the Reheating Cooling Method(RCM) for determining mechanical properties of Al-Mg binary alloys and cast alloy 7050 aluminum in the solid-liquid two phase mushy zone. Using the RCM, it is possible to achieve semi-solid tensile behavior with standard testing equipment and to retain a non-equilibrium casting microstructure, which is necessary to gain insight into hot tearing. Hot tearing, a virtually impossible to repair defect, is known to worsen with increasing Direct Chilled (DC) cast ingot size. Further data gathered from mechanical testing of alloys within the semi-solid mushy zone is necessary to better understand hot tearing and improve ingot production. First, RCM 0.9 fs modulus of toughness results show Al-10%Mg absorbed an average of 240 KJ/m3 while Al-1%Mg an average of 58 KJ/m3. The modulus of toughness at 0.9 fs matches the expected trend seen in hot tearing susceptibility between the two Al-Mg binary alloys. Longer dwell at elevated temperature during heat up is found to decrease an Al-Mg alloy's semi-solid modulus of toughness. Secondly, when above 90% of the non-equilibrium melting point, a basic model of diffusion shows a need for diffusion mitigation. Finally, using 7050 at 0.9 fs, a comparison between the traditional ramp method to the RCM demonstrates an average reduction from 389 KJ/m3 to 10.6 KJ/m3 in modulus of toughness. When compared to the ramp method, the RCM fracture surface contains more evidence of liquid grain boundaries and no sign of plastic deformation, indicating less back diffusion during testing. Increasing strain rate was found to increase specimen modulus of toughness at and above 0.9 fs but lower the modulus of toughness at 0.8 fs. RCM testing shows similarities between the ramp method at 0.9 fs and the mechanical response of the same alloy at 0.95 fs. Date: Tuesday, November 21, 2017 Time: 1:00 P.M. Place: HAMP 2107

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Reminder for Seminar on Monday for Nelyan López Pérez's Preliminary Exam, Monday, Nov. 20, at 10:30 a.m., in ARMS 1021. "Non-Destructive Method for the Detection of Degradation on Ballistic Fibers"
by Son, Rosemary E 17 Nov '17

17 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Non-Destructive Method for the Detection of Degradation on Ballistic Fibers" By Nelyan López Pérez Purdue MSE Ph.D. Preliminary Exam Advisor: Professor John A. Howarter ABSTRACT Ensuring the performance and safety of body armors during service is crucial for institutions such as the United States National Institute of Justice (NIJ). The NIJ's commitment to safety prompts the research of the degradation of high performance fibers like Kevlar, Twaron and Dyneema. Degradation, the reduction of the mechanical properties such as strength and toughness, occurs when a material is exposed to various common environmental factors like sweat, humidity, temperature and sunlight. Currently, the effects of water and pH are studied in Twaron fibers. The amount of water and its effects on their mechanical properties are tested through tensile testing and dynamic mechanical analysis (DMA). However, early stages of degradation can be detected using a technique called positron annihilation lifetime spectroscopy (PALS), which measures the dimensions of free volume in polymers. As the fibers degrade, the dimensions of the free volume change. Hence, PALS can then be used as a complementary technique to the previously mention mechanical tests. Comparing the changes in free volume to those in the mechanical properties gives a broader understanding of the degradation process and rate for high performance fibers, and can later be implemented for the lifetime prediction of new and used body armors. Date: Monday, November 20, 2017 Time: 10:30 A.M. Place: ARMS 1021

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Fwd: Seminar Advertisement
by Donna Bystrom 17 Nov '17

17 Nov '17

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FW: Missing package from Laurell Technologies
by Coar, Stacey L 17 Nov '17

17 Nov '17

Good morning, I am looking for a missing package. The package should have been sent from Laurell Technologies and should have contained the following items: 1. 2 packs of O-rings (100 o-rings per pack) 2. Vacuum Venturi element. This is a small (approximately 1.5" x 2.5") plastic piece. It is likely a dark plastic with several areas cut out from its top face. I have attached an image of what it will likely look like. If you come across this package (or the items described above) please let me know! [cid:image002.jpg@01D35F93.907B3060] Thanks, Mike Toomey

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